We use a slightly modified version of the diskir model of GDP08
so that the disc temperature and normalisation are set by the physical
variables of the mass, distance, mass accretion rate and inner and
outer radii. This has the advantage that the outer radius is set in
terms of physical units, rather than relative to the (possibly
changing) inner radius as in diskir. We parameterise the inner
and outer radii in terms of \(R_g=GM/c^2\) , and leave the inner disc
radius, \(R_{d}\)  as a free parameter in the fits. We fix the mass and
distance at the best (though poorly constrained) estimates of
\(12~M_\odot \)  and 5.4 kpc, respectively [1]}.
